California, the first medical-marijuana state, voted on a legalization measure, Proposition 19, two years ago. It fell three and a half points short, thanks partly to the illicit marijuana growers, who opposed it.

Now come legalization initiatives in Washington, Colorado and Oregon. This state’s I-502 is backed by the American Civil Liberties Union, Seattle City Attorney Peter Holmes and former U.S. Attorneys John McKay and Kate Pflaumer.

Washington’s existing marijuana law, which now makes possession of up to 40 grams — the equivalent weight of the tobacco in two-and-a-half packs of cigarettes — a misdemeanor. Amounts of marijuana greater than that are a felony, as is growing it or selling it.

To be convicted of a felony is to have a serious criminal record, and even a misdemeanor conviction can deprive a university student of federal aid.

Drug convictions have hit particularly hard on African-American and Latino youth, who are equally likely to use marijuana as white youth, but much more likely to be arrested and convicted.

Washington’s medical-marijuana law does not repeal the underlying drug law. It offers an escape from penalties for medical patients with the right sort of permission.

I-502 would authorize marijuana as a commercial product. The state’s Office of Financial Management describes it as a measure to create “a closed, highly regulated industry” of licensed growers, processors and shopkeepers selling a product processed, packaged and branded under state rules.

Of course, marijuana would still be prohibited under the federal Controlled Substances Act — and federal law trumps state law. Because of this, Gov. Chris Gregoire and the men who hope to succeed her, Attorney General Rob McKenna and former U.S. Rep. Jay Inslee — attorneys all — decline to support I-502.

But federal law bans medical marijuana as well. Washington has had medical marijuana because people here voted for it, their local politicians supported them and because federal officials chose to allow it.

I-502 is a way for voters of Washington to push for the next step: legalization.

It is possible that a few weeks from now, Washington, Oregon and Colorado will say to federal authority:

“We intend to decriminalize marijuana for general adult use. We’ll do it a responsible way. We’ll regulate it. We’ll tax it. We’ll keep organized crime out of it. And we intend to do this unless you stop us.”

President Obama — or President Romney — would be under no obligation to agree to this. He might. If he did not, his rejection would make marijuana legalization a live national issue.